Silica-modified Pt/TiO2 catalysts with Tunable Suppression of Strong Metal–Support Interaction for cinnamaldehyde hydrogenation

Tuning Strong Metal-support Interactions (SMSI) is a key strategy to obtain highly active catalysts, but conventional methods usually enable TiO x encapsulation of noble metal components to minimize the exposure of noble metals. This study demonstrates a catalyst preparation method to modulate a weak encapsulation of Pt metal nanoparticles (NPs) with the supported TiO 2 , achieving the moderate suppression of SMSI effects. The introduction of silica inhibits this encapsulation, as reflected in the characterization results such as XPS and HRTEM, while the Ti4 + to Ti3 + conversion due to SMSI can still be found on the support surface. Furthermore, the hydrogenation of cinnamaldehyde (CAL) as a probe reaction revealed that once this encapsulation behavior was suppressed, the adsorption capacity of the catalyst for small molecules like H 2 and CO was enhanced, which thereby improved the catalytic activity and facilitated the hydrogenation of CAL. Meanwhile, the introduction of SiO 2 also changed the surface structure of the catalyst, which inhibited the occurrence of the acetal reaction and improved the conversion efficiency of C=O and C=C hydrogenation. Systematic manipulation of SMSI formation and its consequence on the performance in catalytic hydrogenation reactions are discussed.